The exemplary embodiments of this invention relate generally to magnetic memory structures and, more particularly, to methods and apparatuses for applying Oersted fields to control the local magnetization of magnetic memory structures.
Magnetic memory structures are devices that employ magnetic memory cells. Some magnetic memory cells (for example, magnetic random access memory (MRAM)) include a layer of magnetic film in which the magnetization can be altered and a reference layer of magnetic film in which the magnetization is fixed.
In such devices, conducting wires are arranged in grid form and routed across pluralities of the memory cells arranged as an array. Each memory cell at the intersection of two conducting wires stores a piece of information as an orientation of a magnetization of that particular memory cell. External magnetic fields are applied to change the orientation of magnetization, thereby allowing the magnetization of each memory cell in the magnetic film to assume one of two stable orientations (e.g., “1” or “0”).
One type of external magnetic field that can be applied is an Oersted field. Oersted fields are magnetic fields that are generated by a flow of electrical current through a conducting wire. Oersted fields can be used to produce a dynamic effect on local magnetizations of magnetic memory devices by changing the orientation of magnetization in the magnetic memory device.
However, many magnetic memory devices require large amounts of current flow to generate magnetic fields of suitable strength to affect the local magnetization in a memory cell. Such large amounts of current may lead to the generation of excess heat as well as undesirable degradation in the performance of a device. Additionally, larger amounts of current flow may result in large stray magnetic fields, which may undesirably affect the magnetization of neighboring memory cells.